The sixth biennial Gordon Research Conference on Mammary Gland Biology will be held 8-12 June, 198l at Colby-Sawyer College, New London, N.H. These conferences bring together scientists of many disciplines, all of whom share a major interest in the mammary gland. Their research interests are broadly diversified enabling an interaction that is truly educational and stimulating. Conferences have been held in alternating years since 1971 and attendance for these conferences has: 1971, 50; 1973, 8l; 1975, 76; 1977, 123; and 1979, 183. It should be noted that the large increase in attendance since 1975 probably reflects the continued interest in the need for a multi-disciplinary approach in mammary gland research, and a strong desire of the scientific community to relate this information to the problem of breast cancer. Indeed, it has now become traditional to include several sessions devoted to exciting new developments in the field of mammary cancer and these have been received with enthusiasm, resulting in the fostering of productive interactions amongst the attendees. On the basis of the interest expressed to date, we anticipate attendance of 125 to 150 participants in 198l.